Gaming machines of the type used in casinos typically include coin or token payout mechanisms such as coin hoppers. In hopper-type mechanisms an inclined rotary coin disc or wheel is used to transport coins from a coin storage trough to a coin chute through which the coins are guided to a payout tray. Coin output of the hopper is normally controlled by a coin counter operatively connected to a coin sensing mechanism. For example, U.S. Pat. No. 3,942,544 discloses a mechanical coin sensing mechanism in which a coin, located close to the coin payout chute, deflects a knife which in turn engages a counter. Once the pre-set number of coins have been counted, the coin transport mechanism is automatically shut-down and payout ceases. As an alternative to such mechanical or roller activated switch mechanisms, some coin payout detectors use an optical-electrical switch located at the upper portion of the coin disc. The optical-electrical switch is secured to the hopper by a U-shaped mounting bracket such that the diode light source is adjacent to the coin disc and the light detector is positioned on the other side of the coins on the disc. As the coin passes between the light source and the detector, the light is momentarily blocked by the coin. The detector senses the lack of light and augments the total count of coins paid out. As with mechanical sensors and counters, payout ceases when the number of coins detected equals a predetermined number of coins.
It has been found that under some circumstances the coin detector mechanisms described above do not always provide an accurate count of the coins dispensed by the hopper mechanism. An inaccurate coin count in turn leads to inaccurate payouts in which too few or too many coins are paid out. A need therefore exists for a coin sensing mechanism which can be readily used with various sizes of coins and which accurately senses and counts the number of coins paid out by the gaming machine.